Neuren Pharmaceuticals has reported a record quarter for DAYBUE (trofinetide), with its partner Acadia Pharmaceuticals recording net sales of US$125 million in the second quarter of 2026.
The result marks a 30 per cent increase from the same quarter last year and a 24 per cent rise from the first quarter of 2026. It is the highest quarterly sales result for DAYBUE since its launch and was driven almost entirely by increased patient volume.
Acadia has also raised its full-year 2026 DAYBUE sales guidance to between US$480 million and US$510 million, up from its previous forecast of US$460 million to US$490 million. Based on the revised guidance, Neuren now expects royalty income for the year of between US$53 million and US$56 million, compared with its earlier estimate of US$50 million to US$54 million.
Neuren earned US$12.9 million in royalties during the second quarter, representing a 34 per cent increase from the second quarter of 2025 and a 24 per cent rise from the previous quarter.
The company attributed much of the sales momentum to DAYBUE STIX, a powder formulation of trofinetide that became broadly available in the United States in early April. After an initial limited launch through Rett syndrome Centres of Excellence during the first quarter, demand for STIX strengthened in the second quarter.
By the end of June, 40 per cent of all DAYBUE patients in the United States were receiving STIX. About 45 per cent of STIX demand during the quarter came from new or returning patients, suggesting that the formulation is supporting both the continued treatment of existing patients and the expansion of the overall patient base.
Neuren CEO Jon Pilcher commented: “We are pleased to see an exceptional quarter for DAYBUE, with very strong sales volume growth reflecting the early success of STIX in the US, as well as achievement of the positive CHMP opinion – both important steps toward bringing trofinetide to more patients with Rett syndrome globally. Subject to approval being confirmed, we now look forward to Acadia’s anticipated European launch later this year.”
The company is also preparing for a potential European launch. In late June, the Committee for Medicinal Products for Human Use adopted a positive opinion following a reexamination procedure, recommending that the European Commission grant marketing authorisation for DAYBUE to treat neurobehavioral symptoms associated with Rett syndrome in adults and children aged five years and older.
If approved by the European Commission, the authorisation would cover all 27 European Union member states, along with Iceland, Liechtenstein and Norway. Acadia is expected to launch DAYBUE in Germany in early October through December 2026.
Under the European licensing agreement, Neuren would receive US$35 million following the first commercial sale. The company is also eligible for up to US$170 million in sales milestone payments as annual net sales reach specified thresholds, in addition to tiered royalties ranging from the mid-teens to the low twenties as a percentage of net sales.
In Japan, the topline results from an ongoing trofinetide clinical trial remain on track for release between September and November 2026. Neuren anticipates submitting a regulatory application in Japan during 2027.
Acadia has reaffirmed its target of achieving US$700 million in DAYBUE net sales in 2028. The updated outlook reflects growing demand in the United States, the potential European launch and further international development.
Neuren has granted Acadia an exclusive worldwide licence to develop and commercialise trofinetide. DAYBUE oral solution is approved in the United States, Canada and Israel, while DAYBUE STIX powder is approved by the United States Food and Drug Administration for the treatment of Rett syndrome.
